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N. J. PRITGHARD & J. S. T'EMPLON; DEVICE FOR APPLYING PRESSURE T0 RAILWAY BRAKES.

No. 399,159. Patented Mar. 5, 1889.

(No Model.)

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(No Model.)

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ljnrrnn States Patent NATHANIEL J. PRITCIIART) AND JAMES S. TEMPLON, OF MILNEH, ASQlGNORS, BY DIRECT AND MESNE ASSIGXMENTS TO 'lllhl lRl'lCllARll BPAKE (OM- PANY, OF ROANOKE, "lRGlNIA.

DEViCE FOR APPLYING PRESSURE TO RAiLVVAY-=BRAKES;

SPECIFICATION forming part of Letters Patent No. 399,159, dated March 5, 1889.

Application filed liar-cl. 5, 1888. Renewed January 18, 1889 Serial No. 296,794. 1% lllOdClJ Lo all whom it UNIX/(1072138771.:

Be it known that we, NATHANIEL .l. Putt-L1H- ARD and Janus S. TnnrLoN, citizens of the United States, residing at Milnes, in the county of Page and State of Yirginia, have invented rcri'aii'i new and useful improvements in Devices for \pplyin 4 Pressure to Railway- Brakes; and we do hereby declare the following to be a t'nlh clear, and exact description of the inventiomsiwh aswill enable others skilled in the art to which it appertains to make and use the same. 7

Our invention has reference to a device for use in applying pressure to pneumatic rail- 1 way-brakcs for the purpose of controllingand regulating the admission of air to the brakeeylindcr; and it consists, essentially, in the construction, arrangement, and combination of parts, substantially as will he hereinafter described and claimed.

In the accompanying drawings, illustrating our invention, Figure l is a vertical section of our improved device for applying pressure to pneumatic railway-brakes and shows the piston'valve at the upper limit of its stroke. v

Fig. 2 is a horizontal section on the line .r or

of Fig. 1. Fig. :3 is avertical section similar to that shown in Fig. 1, with the piston-valve 1 occupying the position where air is permitted to pass into the brake-cylinder. Fig. is a perspective view'of the double-ended pistonvalve, together with the graduating or regulating piston. Fig. 5 is a detail view showing in perspective the exhaust-valve used with the piston.

Similar letters of reference designate corresponding parts in all the figures.

A represents a cylinder of any suitable dimensions and made in any desired manner, I it being adapted to be arranged in an upright s position beneath the car with which it is used.

It may he made in one or more parts, as pre- In the drawings the preferable con- 5 i'errcd. struct-ion is shown, consisting of the main cylindrical body, upon the top of which is a cap-plate, A, securely bolted thereto. The 1 bottom of the cylindrical part A is closed by means oi? a plate securely fastened to it and carrying a bulb-shaped air-chambenli, which is calculated to receive at its bottom any drippings or other waste that may QHLUlUlllilll" i therein, whence they are removable through a (llillll-(tOPlI,fl. The ca 'i- 'ilatoA is provided with a cvlindricul extension, t which projects downward [or a certain disiai'ice into the l chamber within the main body A. The wall ot' the cylini'lrical extension. G is provided near l its lower circular periphery with a series of apertures or orifices, g, which may he of any numberdesired. l1 isalso furnished at a suitable point adjacent to the cap-plate A with a small port, Z1.

The cylinder A is provided with ports at i points where the several pipes are coupled, that are used with the ordinary air-brake and lead to the essential parts ol the same.

Thus C denotes the port where a coupling; is made with the pipe which leads to the airdrum or auxiliary reservoir.

D is the port where the pipe is connected leading to the brake-cylinder.

E is a port located in a side wall of the bulb B at a point where it is entered by pipe F, that leads to the main air-supply pipe, and through said pipe F air is introduced into the device.

At port D is connected a T-shaped pipe, as will be seen by reference to Fig. 2. This pipe 1 has a horizontal portion extending out-ward i from the cylinder A, and at right angles to this horizontal portion is another horizontal part, H. At the intersection of these two parts is located a plug-valve, H, which will '1 ordinarily be turned into the position shown 1 in Fig. 2, where air will pass in one direction l or the other between the port D and the pipe l l I, which leads to the brake-cylinder and is coupled to one end of the pipe ll.

A short distance below the port D in the wall oi the main body A is located an exhaustport, 6. Through this exhaust-port the air from the brake-cylinder will have free egress when the brakes are relieved. A vertical l passage, 0, extends upward through thewall l of cylinder A from the bottom of said cylinder to the port C. Near the bottom of the cylinder A communication is established bei tween the interior thereof and the passage 0 i by means of a port, (I, through which air com- ,ing under pressure from the main supplypipe may pass on its way to the air-drum. Near the center of the cap-plate A a port, J, opens centrally into the cylindrical extension G, and communicates with the passage f, running horizontally through the cap-plate and then through the wall of the body A, until it reaches the port D. Vithiu the central ch amber of the device is located a suitably-construct-ed piston. It is preferably made in the form of a double'ended piston having the lower head, L, and the upper head, M, said heads or ends being connected by rods K K. The head M is flanged circumferentially at top and bottom, or otherwise suitably fashioned and shaped to afford an. annular recess capable of receiving an encircling annular ring, N, made in two parts, as shown in Fig. 5, to permit its easy adjustment, said ring serving as an exhaustvalve. The ring. N loosely arranged around the pistonend M. Said ring is recessed at n for a portion ofits circumferential distance, said recessed portion being situated adjacent to the ports D and e, and being of sufiicient size to connect said ports whenever the position of the piston, and consequently ot' the exhaust-valve, is such as to permit of this connection. The vertical length of the exhaust-valve is shorter than the vertical length of theannular space within which it is contained,as will be seen upon inspection of Fig. l; or 3; hence it will be evident that the piston may have a certain amount of vertical movement without displacing the valve from its position.

The object and. purpose of allowing the piston to have a movement independent of any corresponding motion on the part of the valve will be evident hereinafter. The head M of the piston is furthermore constructed in the form of a cylinder, as shown in the drawings. By making the head M of this form the piston is not only lighter, but more space is aiiorded for air within the chamber of body A.

The piston j ustdcscribed may vary considerably in the details of its structure without departing from our invention. \Ve have aimed herein to give a general description of it without being confined to details. The piston has a vertical movement up and down within the central chamber, and in said movement it comes into proper relation to the several ports and passages hereinabove mentioned to accomplish the results which will be farther on more specifically stated. It becomes necessary, however, in order to make our device practically and effectively operative, to provide means whereby the amount of air which is admitted to the brake-cylinder may be graduated, regulated, and governed, so that the engineer may be enabled to set the brakes at a certain desired pressure and keep them at this pressure until he wishes to release them.

Bythe use of the piston alone just described good results may be accomplished in applyiiig the brakes; but the engineer cannot without an auxiliary device automatically measure and maintain any desired amount of pressure upon the brake. In order to do this, we provide a graduating-piston, 0, working within the cylindrical extension Gand adapted to open and close the port Z). A piston-rod, O, is connected to the piston O, and extends vertically downward, passing through a central opening in the head M of the piston, and provided 011 its end with an adjustable nut, P. W hen the piston descends from its uppermost position, the piston end M will strike the nut P and cause the piston O to descend likewise for a certain distance.

It remains to describe the operation of our improved device for applying pressure to pneumatic railway-brakes. WVhen the main piston occupies its uppermost position, as seen in Fig. 1, air can easily pass from the brake cylinder through pipe I to the port D and around through the recess n in the encircling ring N into the exhaust e, where it will escape into the atmosphere. Air coming under pressure through the main air-supply pipe F will enter the air-chamber, pass up underneath the piston, then through the port (1 and passage 0 to the air-drum. Air will likewise, under the same pressure, be upon the top or upper end of the piston, since it will pass through the apertures in the cylindrical part G. Likewise the air will bear upon the piston O, holding it in its uppermost position, so that the port I) will be closed and likewise the port .l. Suppose, now, that it is desired to set the brakes. The engineer will determine the amount of pressure which he desires to apply to the brakes and adjust his regulating-valve accordingly. lVhether a great or less pressure is desired will of course depend upon the circumstances of each case. The proper-manipulation of the engineers valve will exhaust air from beneath the main piston of the device, so that said pressure beneath will be less than the pressure above it. The piston in consequence will begin to descend. In the course of this descent the piston end M will strike the nut P and draw down the piston 0, opening port Z). An outlet 'is thus at once afforded for the air-pressure above the main piston; hence the main piston will cease its further (10\Y11Wc1d movement, while the air above it is rushing through the small port 1) into the space above the piston O, and thence through port J, passage f, and pipe I into the brake-cylinder. The continued outflow of air through the small port I) will in a short time cause the air-pressure in the air-drum and above the main piston to be less than the airpressure beneath the main piston. sult of this inequality of pressures on the upper and lower ends of the main piston will be to cause the latter to adjust itself slightly; hence it will ascend a little, but not enough to displace the valve N from the position shown in Fig. 3, where the port D is closed.

It has already been stated that the main piston is permitted a certain range of move- The rement without interfering with or compelling a change of position of the valve N. After the main piston has risen to the slight extent just referred to it will be evident that the piston end M will no longer be in contact with the nut P, and hence the piston 0 will have its position regulated by the air-pressures above and below it. The air-pressure above the piston 0 will be less than the airprcssure below it, because this pressure below is the same as that in the air-drum, and since the port 3) very small a sufficient amount of air will not have passed through said port to the brake-cylinder in the short interval which has elapsed since it began to flow through said port to make the pressure above the piston O counterbalance the pres.- ure below it. It is therefore clear that the upward pressure on the piston 0 will lift the same and close the port b, thusleaving'a constant pressure applied to thebrakes. The present position of all the parts will now be maintained until the engineer releases the brakes. I l he has applied a ten-pound pressure to his brakes, the graduating-piston, acting in conjunction with the main piston, in the manner just explained, will cause the tenpound pressure, after it has been placed upon the brakes, to be maintained; similarly with a fifteen-pound or thirty-pound pressure, ac cording as the engineer may have adjusted his valve for the one or the other.

Vv'hen it is desired to relieve the brakes, air will be admitted below the main piston, driving the same upward into the position shown in Fig. l, where the recessed ring X connects ports D and c, and enables an outflow of air from the brake-cylinder through the exhaust.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is-

' 1. In a device for applying and relieving the pressure on railwaybrakes, the combina tion of the inclosing-case having ports lead to the air-drum, main pipe, and brakecylinder, the double-ended piston located within said case, the valve surrounding the upper end of the piston, in the manner specified, and the gradtinting-piston, all the parts being combined and arranged for joint operation, substantially as described.

'2. In a device for, applying and relieving the air-pressure to pneumatic railway'brakes, the combination of the cylindrical inclosingcase having ports leading to the air-drum,

main pipe, and brake-cylinder, suitable airpassages, as specified, and also an exhaustport, the cap-plate for said inclosing-case having a downwardly-projecting cylindrical cxtensionprovided with a port and apertures, the main doubleended piston opera-ting within the inclosing-case, and the graduating-piston working within the cylindrical extension on the cap-plate, all substantially as described, and for the purpose set forth,

3. In a device for applying and relieving the air-pressure to air-brakes, the inclosingcase provided with properly-arranged ports, as specified, in combination with the main double-ended piston, its surrounding valve, and the graduating-piston having its pistonrod connected to and actuated by the main piston, substantially in the manner and tor the purpose set forth.

4-. The combination of the inclosing-case having ports leading to the air-drum, main pipe, and brake-cylinder, together with connecting-passages and exhaust-ports, the capplate for said case having a downwardly-projecting cylindrical extension furnished with a small port and other apertures, the main double-ended piston carrying a valve ar ranged relatively thereto, as described, the graduating-piston working in the cylindrical extension on the cap-plate and'having its piston-rod connected to and adapted to be actuated by the main piston, all substantially in the manner and for the purposes hercinbefore described.

5. The combination,with the inclosing-case having ports C D E and exhaust e, the capplate A, having the cylindrical extension G, provided with port Z), and an aperture or apertures, g, said case and cappla-te having also suitable air-passages, of a main piston operating within the central chamber, and a graduating-piston operating within the cylindrical extension on the cap-plate to accomplish'thc result specified, substantially as set forth.

6. The combination of the cylindrical case A, having ports 0 D E and exhaust e, the cap-plate A, having the extension G, provided with small port I), and an aperture or apertures, 5 the main piston having suitably-connected heads L and M, said head M being peripherally flanged at top and bottom to form an annular recess, the valve N, located within said annular recess, and the piston 0, working within the extension G and having a piston-rod, O, projected through the head M and furnished with a nut, P, all the parts being arranged substantially an d for the purpose described.

7.111 combination with an inclosing-case constructed substantially as described, a main piston having heads L and M, said head M being annular-1y recessed, the valve N, recessed at n and located within the said annular recess of head M, but being shorter in vertical length than the recess, for the purpose indicated, and the piston 0, having rod 0, extending through head M and furnished with nut P, all substantially as described.

In testimony whereof we at'fix our signatures in presence of two witnesses.

NATHANIEL J. PRlTCl-IARD. JAS. S. TEMPLON. 'Witnesscs:

Win. HAYS, J. O. I-lnnns. 

